import Vue from 'vue'
// 导入组件
import CopyFileDialog from './Dialog.vue'
// 使用基础 Vue 构造器，创建一个“子类”
const CopyFileConstructor = Vue.extend(CopyFileDialog)

let copyFileInstance = null
/**
 * 初始化复制文件实例
 * @param {object | array} fileInfo 要复制的文件信息
 */
const initInstanceCopyFile = (fileInfo) => {
  copyFileInstance = new CopyFileConstructor({
    el: document.createElement('div'),
    data() {
      return {
        fileInfo
      }
    }
  })
}
/**
 * 复制文件 Promise 函数
 * @returns {Promise} 抛出确认和取消回调函数
 */
const showCopyFileDialog = (obj) => {
  // 非首次调用服务时，在 DOM 中移除上个实例
  if (copyFileInstance !== null) {
    document.body.removeChild(copyFileInstance.$el)
  }
  const { fileInfo } = obj
  return new Promise((reslove) => {
    initInstanceCopyFile(fileInfo)
    copyFileInstance.callback = (res) => {
      reslove(res)
      // 服务取消时卸载 DOM
      if (res === 'cancel' && copyFileInstance !== null) {
        document.body.removeChild(copyFileInstance.$el)
        copyFileInstance = null
      }
    }
    document.body.appendChild(copyFileInstance.$el) //  挂载 DOM
    Vue.nextTick(() => {
      copyFileInstance.visible = true //  打开对话框
    })
  })
}

export default showCopyFileDialog
